A four-inch sprinkler system pipe had burst above a tank containing an unknown quantity of nitric hydrofluoric acid, he said. A lid on the tank stopped most of the water from entering it.

But a small amount of the chemical – which can cause severe burns and possible respiratory problems – contaminated the water, Ohashi said.

Company employees were evacuated and one person later went to a hospital with possible symptoms. As of Saturday evening, Ohashi was uncertain of the person’s condition.

Eight other people had not reported problems as of that night, he added.

Some of the contaminated water entered a storm drain system. But fire crews worked fast enough to stop the water from leaving the company’s property. A private company was called to remove the contaminated water.

GKN uses the liquid acid with metals that the company makes for military aircraft, Ohashi said.